Measurement device and operation method thereof

ABSTRACT

Provided herein are a measurement device and an operation method thereof. The measurement device senses a distance variation between the measurement device and an object using a built-in proximity sensor and accordingly determines whether to turn on or turn off a track sensing module and an optical ranging module such that the measurement device provides intelligent selection to achieve energy saving without being interfered with by other sensors being turned on.

BACKGROUND 1. Technical Field

The present invention generally relates to a measurement device and anoperation method thereof and, more particularly, to a measurement deviceproviding optical ranging and track sensing and an operation method ofthe measurement device.

2. Description of Related Art

Conventionally, a measurement device based on optical ranging emitssensing light on an object and estimates the time of flight (TOF) forlight travelling between the measurement device and the object afterreceiving the sensing light reflected by the object so as to calculate adistance between the measurement device and the object.

However, the optical ranging fails to calculate the surface length ofthe object according to the sensing light reflected by the object.Therefore, in the case the surface length of the object is required itis not possible to simply use the measurement device. In view of this,there is a need for providing a measurement device capable ofcalculating the surface length of the object.

SUMMARY

One embodiment of the present invention provides a measurement device.The measurement device includes a roller, at least one proximity sensor,a track sensing module, an optical ranging module and a processor. Theroller is disposed at a bottom of the measurement device. The proximitysensor is configured to sense a proximity status between the measurementdevice and an object and accordingly provide an estimated distance. Thetrack sensing module is disposed in the measurement device and isconfigured to continuously capture a plurality of reference pictures ofa regional surface of the roller and calculate a track length of themeasurement device according to the plurality of reference pictures. Theoptical ranging module is also disposed in the measurement device and isconfigured to emit a light beam towards the outside of the measurementdevice and calculate a distance data according to the light beam beingreflected. The processor is coupled among the proximity sensor, thetrack sensing module and the optical ranging module and is configured toselectively turn on or turn off the track sensing module and the opticalranging module according to the estimated distance. When the estimateddistance is smaller than a first pre-determined threshold, the processorturns on the track sensing module and turns off the optical rangingmodule. When the estimated distance is larger than a secondpre-determined threshold, the processor turns off the track sensingmodule and turns on the optical ranging module.

One embodiment of the present invention further provides an operationmethod for a measurement device. The operation method includes steps asfollows. A proximity sensor senses a proximity status between themeasurement device and an object and accordingly provides an estimateddistance. A processor selectively turns on or turns off the tracksensing module and the optical ranging module according to the estimateddistance. When the estimated distance is smaller than a firstpre-determined threshold, the processor turns on the track sensingmodule and turns off the optical ranging module. When the estimateddistance is larger than a second pre-determined threshold, the processorturns off the track sensing module and turns on the optical rangingmodule.

In view of the above, the present invention provides a measurementdevice and an operation method thereof, capable of sensing a distancevariation between the measurement device and an object using a built-inproximity sensor and accordingly determining whether to turn on or turnoff a track sensing module and an optical ranging module such that themeasurement device provides intelligent selection to achieve energysaving without being interfered with by other sensors being turned on.In addition, the measurement device in the present invention uses therotation of the roller to acquire a relative movement on the surface ofan object, and the track calculated by the built-in track sensing moduleis based on a plurality of reference pictures of a regional surface ofthe roller. The measurement device in the present invention canprecisely calculate a track length of the measurement device along thesurface of the object.

In order to further understand the techniques, means and effects of thepresent invention, the following detailed descriptions and appendeddrawings are hereby referred to, such that, and through which, thepurposes, features and aspects of the present invention can bethoroughly and concretely appreciated; however, the appended drawingsare merely provided for reference and illustration, without anyintention to be used for limiting the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present invention, and are incorporated in andconstitute a part of this specification. The drawings illustrateexemplary embodiments of the present invention and, together with thedescription, serve to explain the principles of the present invention.

FIG. 1 is a block diagram of a measurement device according to oneembodiment of the present invention;

FIG. 2 is a schematic diagram of a measurement device according to oneembodiment of the present invention;

FIG. 3A is a block diagram of a proximity sensor in a measurement deviceaccording to one embodiment of the present invention;

FIG. 3B is a block diagram of a proximity sensor in a measurement deviceaccording to another embodiment of the present invention;

FIG. 4 is a block diagram of a track sensing module in a measurementdevice according to one embodiment of the present invention;

FIG. 5 is a schematic diagram of a measurement device according toanother embodiment of the present invention;

FIG. 6 is a block diagram of an optical ranging module in a measurementdevice according to one embodiment of the present invention;

FIG. 7 is a flowchart of an operation method according to one embodimentof the present invention;

FIG. 8 is a flowchart of turning on or turning off a track sensingmodule and an optical ranging module in an operation method according toone embodiment of the present invention;

FIG. 9 is a block diagram of a track sensing system according to oneembodiment of the present invention;

FIG. 10 is a perspective view of a base in a track sensing systemaccording to one embodiment of the present invention;

FIG. 11 is a flowchart of a track sensing method according to oneembodiment of the present invention;

FIG. 12 is a block diagram of a wireless charging device providingproximity sensing according to one embodiment of the present invention;and

FIG. 13 is a schematic diagram of a wireless charging device providingproximity sensing according to one embodiment of the present invention.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The detailed description set forth below in connection with the appendeddrawings is intended as a description of certain embodiments of thepresent invention, and is not intended to represent the only forms thatmay be developed or utilized. The description sets forth the variousfunctions in connection with the illustrated embodiments, but it is tobe understood, however, that the same or equivalent functions may beaccomplished by different embodiments that are also intended to beencompassed within the scope of the present invention.

Referring to FIG. 1 and FIG. 2, FIG. 1 is a block diagram of ameasurement device according to one embodiment of the present inventionand FIG. 2 is an operational diagram of a measurement device accordingto one embodiment of the present invention. The measurement device 1includes a roller 10, at least one proximity sensor 12, a track sensingmodule 14, an optical ranging module 16 and a processor 18. The tracksensing module 14, the optical ranging module 16 and the processor 18can be implemented by hardware circuitry, or by hardware circuitry withfirmware or with software implemented by hardware circuitry, or byhardware circuitry with firmware or with software. In brief, the presentinvention is not limited to the implementation of the measurement device1. Moreover, the track sensing module 14, the optical ranging module 16and the processor 18 can be integrated or discretely disposed, to whichthe present invention is not limited. In addition, the positions wherethe roller 10, the proximity sensor 12, the track sensing module 14, theoptical ranging module 16 and the processor 18 are disposed in themeasurement device 1 are not limited to the examples in FIG. 1 or FIG.2. A person with ordinary skill in the art may make any designsaccording to practical demands or applications.

More particularly, the roller 10 is disposed at a bottom of themeasurement device 1. The roller 10 is further disposed against thesurface of an object 2, such that the measurement device 1 moves alongthe surface of the object 2 with the rotation of the roller 10, as shownin FIG. 2. It should be noted that the present invention is not limitedto the implementation of the roller 10. A person with ordinary skill inthe art may make any designs according to practical demands orapplications. Therefore, the detailed description of the roller 10 isnot presented herein.

Furthermore, the proximity sensor 12 is configured to sense a proximitystatus between the measurement device 1 and the object 2 and accordinglyprovide an estimated distance D_(E). It should be noted that, in aspecific embodiment, the proximity sensor 12 senses periodically, forexample, every other second or every other half second, to determine theproximity status between the measurement device 1 and the object 2, towhich the present invention is not limited. Then, the track sensingmodule 12 is disposed in the measurement device 1 and is configured tocontinuously capture a plurality of reference pictures of a regionalsurface of the roller 10 and calculate a track length of the measurementdevice 1 along the surface of the object 2 according to the plurality ofreference pictures.

The optical ranging module 16 is also disposed in the measurement device1 and is configured to emit a light beam towards the outside of themeasurement device 1 and calculate a distance data according to thelight beam being reflected. The processor 18 is coupled among theproximity sensor 12, the track sensing module 14 and the optical rangingmodule 16 and is configured to selectively turn on or turn off the tracksensing module 14 and the optical ranging module 16 according to theestimated distance D_(E) provided by the proximity sensor 12. When theestimated distance D_(E) is smaller than a first pre-determinedthreshold, the processor 18 turns on the track sensing module 14 andturns off the optical ranging module 14. When the estimated distanceD_(E) is larger than a second pre-determined threshold, the processor 18turns off the track sensing module 14 and turns on the optical rangingmodule 16.

Therefore, according to the teachings stated above, a person withordinary skill in the art would understand that one of the goals of thepresent invention is that the built-in proximity sensor 12 in themeasurement device 1 is used to acquire the estimated distance D_(E)between the measurement device 1 and the object 2 and the processor 18is used to analyze the estimated distance D_(E) so as to determinewhether to turn on the track sensing module 14 to sense the movement ofthe measurement device 1 along the surface of the object 2 or whether toturn on the optical ranging module 16 to sense the distance between themeasurement device 1 and the object 2. In view of this, compared to theconventional art which only provides a single technique, the measurementdevice 1 of the present invention provides two techniques to bring forthmore convenience.

Furthermore, the basic principle of the proximity sensor 12 is that themeasurement device 1 determines whether to move closer to or away fromthe object 2. Accordingly, a person with ordinary skill in the art wouldunderstand that the estimated distance D_(E) provided by the proximitysensor 12 does not effectively indicate the actual distance between themeasurement device 1 and the object 2. Moreover, the present inventionis not limited to the units (for example, cm, m, and so forth) for theestimated distance D_(E). In other words, a person with ordinary skillin the art may design the estimated distance D_(E) according topractical demands or applications.

However, to further describe the proximity sensor 12 in detail, thepresent invention provides two implementations of the proximity sensor12. Referring to FIG. 3A, FIG. 3A is a block diagram of a proximitysensor in a measurement device according to one embodiment of thepresent invention. The proximity sensor 12 includes an emitter unit 120and a receiver unit 122. The proximity sensor 12 in FIG. 3A uses theemitter unit 120 to emit an optical signal L, which is then reflected bythe object 2 to the receiver unit 122, such that the receiver unit 122determines the proximity status (closer or away) between the measurementdevice 1 and the object 2 according to an intensity variation of thereceived optical signal L to correspondingly provide the estimateddistance D_(E).

Moreover, referring to FIG. 3B, FIG. 3B is a block diagram of aproximity sensor in a measurement device according to another embodimentof the present invention. Compared to the proximity sensor 12 in FIG.3A, the proximity sensor 12 in FIG. 3B includes an image capture unit124 and a pixel processing unit 126. The proximity sensor 12 in FIG. 3Buses the image capture unit 124 to capture an image of the object 2 anduses the pixel processing unit 126 to calculate a number of pixelclusters occupied by the object 2 according to the image. Then, thepixel processing unit 126 determines the proximity status (closer oraway) between the measurement device 1 and the object 2 according to thenumber of pixel clusters to correspondingly provide the estimateddistance D_(E). Practically, the object 2 has a fixed structure, suchthat it can be identified by the pixel processing unit 126. If themeasurement device 1 moves closer to the object 2, the image of theobject 2 is larger, which results in a larger number of pixel clustersoccupied by the object 2. On the contrary, if the measurement device 1moves away from the object 2, the image of the object 2 is smaller,which results in a smaller number of pixel clusters occupied by theobject 2.

Therefore, according to the teachings stated above, a person withordinary skill in the art would know that the proximity sensor 12 inFIG. 3A determines whether the measurement device 1 moves closer to oraway from the object 2 according to the intensity variation of thereceived optical signal L. In FIG. 3B, the proximity sensor 12determines whether the measurement device 1 moves closer to or away fromthe object 2 according to the variation of the number of pixel clustersoccupied by the object 2. To sum up, the above implementations onlyexemplify, with no intention to limit, the present invention. A personwith ordinary skill in the art may design the proximity sensor 12according to practical demands or applications.

On the other hand, referring again to FIG. 2, when the user wants toacquire the track length of the measurement device 1 along the surfaceof the object 2, the user has to move the measurement device 1 close tothe object 2 until the roller 10 is disposed against the surface of theobject 2. Therefore, when the estimated distance D_(E) is smaller than afirst pre-determined threshold (for example, 3 cm), the measurementdevice 1 of the present invention uses the built-in processor 18 to turnon the track sensing module 14 to measure the displacement of themeasurement device 1 along the surface of the object 2. Moreover, toachieve energy saving without being interfered with by other sensorsbeing turned on, the processor 18 can turn off the control opticalranging module 16 at the same time when the processor 18 has determinedto turn on the track sensing module 14 to measure the displacement ofthe measurement device 1.

On the contrary, when the user wants to acquire the actual distance databetween the measurement device 1 and the object 2, the user has to keepthe measurement device 1 and the object 2 still, such that the opticalranging module 16 can measure the time of flight. Therefore, when theestimated distance D_(E) is larger than a second pre-determinedthreshold (for example, 7 cm), the measurement device 1 of the presentinvention uses the built-in processor 18 to turn on the optical rangingmodule 16 to measure the actual distance between the measurement device1 and the object 2. Similarly, when processor 18 has determined to turnon the optical ranging module 16, the processor 18 can turn off thecontrol track sensing module 14 at the same time to avoid unnecessarypower consumption and inference. In view of this, the secondpre-determined threshold is larger than or equal to the firstpre-determined threshold.

However, to describe the track sensing module 14 in detail, the presentinvention further provides an implementation of the track sensing module14. Referring to FIG. 4, FIG. 4 is a block diagram of a track sensingmodule in a measurement device according to one embodiment of thepresent invention. It should be noted that the implementation of thetrack sensing module 14 in the measurement device 1 only exemplifies,with no intention to limit, the present invention. Moreover, the tracksensing module 14 is operable in the operational diagram in FIG. 2.Please refer to FIG. 2 for better understanding. In addition, elementsin FIG. 4 that are identical to those in FIG. 1 are labeled in the sameway, and descriptions thereof are thus not repeated.

The track sensing module 14 includes a light source 140, an imagesensing circuit 142 and an image analysis circuit 144. The image sensingcircuit 142 and the image analysis circuit 144 can be implemented byhardware circuitry, or by hardware circuitry with firmware or withsoftware implemented by hardware circuitry, or by hardware circuitrywith firmware or with software. To sum up, the present invention is notlimited to the implementation of the track sensing module 14. Moreover,the light source 140, the image sensing circuit 142 and the imageanalysis circuit 144 can be integrated or discretely disposed, to whichthe present invention is not limited. Moreover, the positions where thelight source 140 and the image sensing circuit 142 are disposedcorresponding to the roller 10 are not limited to the examples in FIG.4. A person with ordinary skill in the art may make any designsaccording to practical demands or applications.

More particularly, the light source 140 is configured to illuminate aregional surface R1 of the roller 10. The image sensing circuit 142 isconfigured to capture the plurality of reference pictures of theregional surface R1 illuminated by the light source 140 based on a fixedsampling cycle. The image analysis circuit 144 is configured to comparethe plurality of reference pictures based on at least one texturalfeature of the plurality of reference pictures to acquire anillumination track of the light source 140 on the roller 10 andcalculate the track length of the measurement device 1 along the surfaceof the object 2 according to the illumination track.

Furthermore, a conventional optical navigation device (for example, anoptical mouse) similarly illuminates a surface and uses an image sensingcircuit to capture a plurality of continuous pictures of the surface.The continuous pictures are then compared and analyzed to determine adisplacement of the optical navigation device within a time period andperform navigation according to the cursor on a displacement controlpanel. Therefore, according to the teachings stated above, a person withordinary skill in the art would understand that the principle of thetrack sensing module 14 of the present invention is similar to that ofthe conventional optical navigation device. However, compared to theconventional optical navigation device, the measurement device 1 of thepresent invention moves along the surface of the object 2 with therotation of the roller 10. Therefore, the continuous pictures capturedby the image sensing circuit 142 correspond to the reference pictures inthe regional surface R1 of the roller 10 illuminated by the light source140. In view of this, even if the surface of the object 2 is irregular,the track sensing module 14 still can precisely calculate the tracklength of the measurement device 1 along the surface of the object 2. Itshould be noted that the technology of acquiring the illumination trackof the light source 140 by comparing a plurality of reference picturesis known to the person with ordinary skill in the art. Therefore,detailed descriptions of the above are not repeated.

On the other hand, referring to FIG. 5, FIG. 5 is an operational diagramof a measurement device according to another embodiment of the presentinvention. As previously stated, when the user wants to acquire anactual distance data D_(R) between the measurement device 1 and theobject 2, the measurement device 1 of the present invention uses thebuilt-in processor 18 to turn on the optical ranging module 16 (and,meanwhile, turn off the track sensing module 14) to measure the time offlight between the measurement device 1 and the object 2 because theestimated distance D_(E) is larger than the second pre-determinedthreshold.

Furthermore, referring to FIG. 6, FIG. 6 is a block diagram of anoptical ranging module in a measurement device according to oneembodiment of the present invention. It should be noted that theimplementation of the optical ranging module 16 in the measurementdevice 1 only exemplifies, with no intention to limit, the presentinvention. Moreover, the optical ranging module 16 is operable in theoperational diagram in FIG. 5. Please refer to FIG. 5 for betterunderstanding. In addition, elements in FIG. 5 that are identical tothose in FIG. 1 are labeled in the same way, and descriptions thereofare thus not repeated.

The optical ranging module 16 includes a light-emitting device 160, anoptical sensor device 162, a control circuit 164 and a distancecalculating circuit 166. The control circuit 164 and the distancecalculating circuit 166 can be implemented by hardware circuitry, or byhardware circuitry with firmware or with software implemented byhardware circuitry, or by hardware circuitry with firmware or withsoftware. To sum up, the present invention is not limited to theimplementation of the optical ranging module 16. Moreover, thelight-emitting device 160, the optical sensor device 162, the controlcircuit 164 and the distance calculating circuit 166 can be integratedor discretely disposed, to which the present invention is not limited.Moreover, the positions where the light-emitting device 160, the opticalsensor device 162, the control circuit 164 and the distance calculatingcircuit 166 are disposed in the measurement device 1 are not limited tothe examples in FIG. 6. A person with ordinary skill in the art may makeany designs according to practical demands or applications.

More particularly, the light-emitting device 160 is configured to emitthe light beam L_(ID) towards the outside of the measurement device 1 toreach the surface of the object 2. The optical sensor device 162 isconfigured to sense and accumulate an energy of the light beam L_(RD)being reflected according to a shutter cycle signal S_(ST) tocorrespondingly provide an optical sensing signal S_(LS1). Practically,the light-emitting device 160 may be a light-emitting diode (LED), andthe light-emitting device 160 emits the light beam L_(ID) to the surfaceof the object 2 according to a lighting cycle signal S_(LD). Forexample, when the lighting cycle signal S_(LD) is at a high level, thelight-emitting device 160 emits the light beam L_(ID) to the surface ofthe object 2. On the contrary, when the lighting cycle signal S_(LD) isat a low level, the light-emitting device 160 does not emit the lightbeam L_(ID) to the surface of the object 2.

On the other hand, the optical sensor device 162 may be a charge coupleddevice (CCD) or a complementary metal-oxide-semiconductor (CMOS) opticalsensor device. The optical sensor device 162 senses and accumulates anenergy of the light beam L_(RD) being reflected according to a shuttercycle signal S_(ST) to correspondingly provide an optical sensing signalS_(LS1). In addition, the optical sensor device 162 determines whetherto provide the optical sensing signal S_(LS1) according to a read signalS_(RE).

For example, when the shutter cycle signal S_(ST) is at a high level,the optical sensor device 162 senses and accumulates the energy of thelight beam L_(RD) being reflected. On the contrary, when the shuttercycle signal S_(ST) is at a low level, the optical sensor device 162does not sense and accumulate the energy of the light beam L_(RD) beingreflected. Moreover, when read signal S_(RE) indicates “having beenread”, the optical sensor device 162 outputs an optical sensing signalS_(LS1) according to the accumulated energy of the reflected light beamL_(RD). It should be noted that, when the read signal S indicates“having been read”, the optical sensor device 162 resets the accumulatedenergy of the reflected light beam L_(RD) (i.e., the optical sensordevice 162 will release the accumulated energy) after the optical sensordevice 162 outputs the optical sensing signal S_(LS1).

Furthermore, the control circuit 164 is configured to control thelight-emitting device 160 to continuously emit the light beam L_(ID) tothe surface of the object 2 within a light-emitting period and switchthe shutter cycle signal S_(ST) to a high level state within a sensingperiod after the light-emitting device 160 has emitted the light beamL_(ID) for a delayed period, such that the optical sensor device 162senses and accumulates the energy of the light beam L_(RD) beingreflected and accordingly provides the optical sensing signal S_(LS1).Then, the distance calculating circuit 166 is configured to acquire atime-of-flight (TOF) data between the measurement device 1 and theobject 2 according to the energy of the light beam L_(ID) emitted by thelight-emitting device 160 within the light-emitting period and theoptical sensing signal S_(LS1), and calculate the distance data D_(R)between the measurement device 1 and the object 2 according to thetime-of-flight data. It should be noted that the technologies ofacquiring the time of flight based on the energy variation of light andcalculating the distance according to the time of flight are known tothe person with ordinary skill in the art. Therefore, detaileddescriptions of the above are not repeated. To sum up, the aboveimplementations only exemplify, with no intention to limit, the presentinvention. A person with ordinary skill in the art may design theoptical ranging module 16 according to practical demands orapplications.

On the other hand, referring back to FIG. 1, the measurement device 1further includes a display module 19. The display module 19 isconfigured to display the distance data D_(R) calculated by the opticalranging module 16 and/or the track length calculated by the tracksensing module 14. Practically, the display module 19 may be a touchdisplay or a non-touch display, to which the present invention is notlimited. A person with ordinary skill in the art may make any designsaccording to practical demands or applications.

In addition, to describe the operation for the measurement device in theprevious embodiments, the present invention further provides anoperation method. Referring to FIG. 7, FIG. 7 is a flowchart of anoperation method according to one embodiment of the present invention.The method can be performed with the measurement device 1 in FIG. 1.Therefore, please refer to FIG. 1 for better understanding.

First, in Step S701, a proximity sensor is used to sense a proximitystatus between the measurement device and an object and accordinglyprovide an estimated distance. Then, in Step S703, a processor is usedto selectively turn on or turn off the track sensing module and theoptical ranging module according to the estimated distance. When theestimated distance is smaller than a first pre-determined threshold, theprocessor turns on the track sensing module and turns off the opticalranging module. When the estimated distance is larger than a secondpre-determined threshold, the processor turns off the track sensingmodule and turns on the optical ranging module.

It should be noted that, in one embodiment of the present invention, thesecond pre-determined threshold is larger than or equal to the firstpre-determined threshold. Moreover, referring to FIG. 8, FIG. 8 is aflowchart of turning on or turning off a track sensing module and anoptical ranging module in an operation method according to oneembodiment of the present invention. Steps in FIG. 8 that are identicalto those in FIG. 7 are labeled in the same way, and descriptions thereofare thus not repeated.

Furthermore, Step S703 includes Step S801 to Step S811. First, in StepS801, the processor determines whether the estimated distance is smallerthan the first pre-determined threshold. In Step S803, if the estimateddistance is smaller than the first pre-determined threshold, theprocessor turns on the track sensing module and turns off the opticalranging module to perform Step S805. In Step S805, the track sensingmodule is used to continuously capture a plurality of reference picturesof a regional surface of the roller and calculate a track length of themeasurement device along the surface of the object according to theplurality of reference pictures. On the contrary, in Step S807, theprocessor determines whether the estimated distance is larger than thesecond pre-determined threshold if the estimated distance is not smallerthan the first pre-determined threshold.

Next, in Step S809, if the estimated distance is larger than the secondpre-determined threshold, the processor turns off the track sensingmodule and turns on the optical ranging module to perform Step S811. InStep S811, the optical ranging module is used to emit a light beamtowards the outside of the measurement device and calculate a distancedata between the object and the measurement device according to thelight beam being reflected.

As previously stated, the present invention provides a measurementdevice and an operation method thereof, capable of sensing a distancevariation between the measurement device and an object using a built-inproximity sensor and accordingly determining whether to turn on or turnoff a track sensing module and an optical ranging module such that themeasurement device provides intelligent selection to achieve energysavings without being interfered with by other sensors being turned on.In addition, the measurement device in the present invention uses therotation of the roller to acquire a relative movement on the surface ofan object, and the track calculated by the built-in track sensing moduleis based on a plurality of reference pictures of a regional surface ofthe roller. The measurement device in the present invention canprecisely calculate a track length of the measurement device along thesurface of the object.

On the other hand, as previously stated, compared to the conventionaloptical navigation device, one of the goals of the present invention isto capture a plurality of reference pictures of a regional surface ofthe roller illuminated by the light source capture. In view of this, thepresent invention further provides a track sensing system. Referring toFIG. 9 and FIG. 10, FIG. 9 is a block diagram of a track sensing systemaccording to one embodiment of the present invention and FIG. 10 is aperspective view of a base in a track sensing system according to oneembodiment of the present invention.

The track sensing system 9 includes a base 90, a disk 92, a tracksensing module 94 and a movement identification module 96. The tracksensing module 94 and the movement identification module 96 can beimplemented by hardware circuitry, or by hardware circuitry withfirmware or with software implemented by hardware circuitry, or byhardware circuitry with firmware or with software. To sum up, thepresent invention is not limited to the implementation of the tracksensing system 9. Moreover, the above elements can be integrated ordiscretely disposed, to which the present invention is not limited.

More particularly, the base 90 is a casing, such that the track sensingsystem 9 can be formed as an electronic device. Therefore, the presentinvention is not limited to the implementation of the base 90. A personwith ordinary skill in the art may make any designs according topractical demands or applications. Therefore, the base 90 will not bedescribed in detail herein. In addition, to form the track sensingsystem 9 as a wearable electronic device, the track sensing system 9 hasto further include a ring body (not shown). The ring body is configuredto install the base 90 on a movable portion (for example, the wrist) ofthe user. To sum up, the present invention is not limited to theimplementation of the track sensing system 9 as an electronic device. Aperson with ordinary skill in the art may make any designs according topractical demands or applications.

Moreover, as shown in FIG. 10, the disk 92 is disposed planarly on asurface of the base 90 and is capable of being rotated and/or pressed onat least one portion on the disk 92 by the user. The track sensingmodule 94 is configured to continuously capture a plurality of referencepictures of a regional surface R1′ of the disk 92 and calculate adisplacement and/or a pressure of/on the disk 92 rotated and/or pressedby the user according to the plurality of reference pictures. Last, themovement identification module 96 is configured to determine a movementof the user according to the displacement and/or the pressure.

Furthermore, the track sensing module 94 in the present embodiment isimplemented similarly to the track sensing module 14 in FIG. 4.Therefore, the track sensing module 94 will not be described in detailherein. In brief, the track sensing module 94 in the present embodimentsimilarly includes a light source 140, an image sensing circuit 142 andan image analysis circuit 144.

It should be noted that, compared to the roller 10 illuminated by thelight source 140 in FIG. 4, the disk 92 in the present embodiment isilluminated by the light source 140. Therefore, in the presentembodiment, the regional surface R1′ is defined as a regional surface ona lateral plane of the disk 92, as shown in FIG. 10. Similarly, theimage sensing circuit 142 is configured to capture the plurality ofreference pictures of the regional surface R1′ illuminated by the lightsource 140 according to a fixed sampling cycle. Then, the image analysiscircuit 144 is configured to compare the plurality of reference picturesbased on at least one textural feature of the plurality of referencepictures to acquire an illumination track (for example, horizontal orvertical) of the light source 140 on the disk 92 on a lateral plane andcalculate the displacement and/or the pressure of/on the disk 92 rotatedand/or pressed by the user according to the illumination track.

However, in other embodiments, the regional surface R1′ may also bedefined as a regional surface of a bottom surface (not shown) of thedisk 92, to which the present invention is not limited. Therefore, thereference pictures of the regional surface R1′ captured by the imagesensing circuit 142 indicate the reference pictures of a bottom surfaceof the disk 92 illuminated by the light source 140. Then, the imageanalysis circuit 144 compares the plurality of reference pictures basedon at least one textural feature of the plurality of reference picturesto acquire an illumination track of the light source on the bottomsurface of the disk 92 and calculate the displacement of the disk 92rotated by the user according to the illumination track.

In the previous embodiments, the user may also press on at least oneportion on the disk 92. Therefore, the track sensing module 94 in thepresent embodiment may also calculate the pressure pressed on the disk92 by the user (i.e., the force applied by the user) according to theintensity variation of light in the regional surface R1′. For example,the track sensing module 94 may further include at least one opticalsensor device (not shown). The optical sensor device is configured tosense and accumulate the intensity variation of light in the regionalsurface R1′. Accordingly, the image analysis circuit 144 calculates thepressure on the disk 92 pressed by the user according to the intensityvariation of light from the light source 140 as analyzed by the opticalsensor device. It should be noted that the present invention is notlimited to the calculation of the pressure. Therefore, according to theteachings stated above, the person with ordinary skill in the art shouldunderstand that the previous implementations only exemplify, with nointention to limit, the present invention. The person with ordinaryskill in the art may design the calculations of the pressure and thedisplacement according to practical demands or applications.

Moreover, referring again to FIG. 9, the base 90, the disk 92, the tracksensing module 94 and the movement identification module 96 can beintegrated to form an electronic device. The track sensing system 9further includes a processor module (not shown) disposed in theelectronic device. The processor module is configured to control theelectronic device to execute a function corresponding to the movementdetermined by the movement identification module 96.

To describe the operation of the track sensing system, the presentinvention further provides a track sensing method. Referring to FIG. 11,FIG. 11 is a flowchart of a track sensing method according to oneembodiment of the present invention. The track sensing method isoperable with the track sensing system 9 in FIG. 9. Please refer to FIG.9 for better understanding. In addition, steps in FIG. 11 that areidentical to those in previous embodiments will not be repeated.

First, in Step S111, the track sensing module is used to continuouslycapture a plurality of reference pictures of a regional surface of thedisk and calculate a displacement and/or a pressure of/on the diskrotated and/or pressed by the user according to the plurality ofreference pictures. Then, in Step S113, the movement identificationmodule is used to determine a movement of the user according to thedisplacement and/or the pressure.

As previously stated, the present invention provides a track sensingsystem and a track sensing method using a built-in track sensing moduleto sense the illumination track of the light source on the disk andaccordingly calculate the displacement and/or the pressure of/on thedisk 92 rotated and/or pressed by the user to further determine amovement of the user. Therefore, compared to the conventional art, thetrack sensing system of the present invention is less interfered with bynoise to achieve better movement identification.

On the other hand, as previously stated, the principle of the proximitysensor is to determine whether an object is moving closer or away. Inview of this, the present invention further provides a wireless chargingdevice capable of providing proximity sensing. Referring to FIG. 12 andFIG. 13, FIG. 12 is a block diagram of a wireless charging deviceproviding proximity sensing according to one embodiment of the presentinvention and FIG. 13 is an operational diagram of a wireless chargingdevice providing proximity sensing according to one embodiment of thepresent invention.

The wireless charging device 13 includes a charging module 130, at leastone proximity sensor 132 and a central controller 134. The chargingmodule 130, the proximity sensor 132 and the central controller 134 canbe implemented by hardware circuitry, or by hardware circuitry withfirmware or with software implemented by hardware circuitry, or byhardware circuitry with firmware or with software. To sum up, thepresent invention is not limited to the implementation of the wirelesscharging device 13. Moreover, the above elements can be integrated ordiscretely disposed, to which the present invention is not limited.

More particularly, the charging module 130 configured to performwireless charging on the object 2′ (for example, a mobile communicationdevice in FIG. 13). The proximity sensor 132 is configured to sense aproximity status between the wireless charging device 13 and the object2′ and accordingly provide an estimated distance. It should be notedthat, in one specific embodiment, the proximity sensor 132 canperiodically sense the proximity status between the wireless chargingdevice 13 and the object 2′ and accordingly provide the estimateddistance, for example, every other second, every other half second, andso forth, to which the present invention is not limited.

Moreover, the central controller 134 is coupled between the chargingmodule 130 and the proximity sensor 132. The central controller 134 isconfigured to selectively turn on or turn off the control chargingmodule 130 according to the estimated distance. The central controller134 turns on the charging module 130 when the estimated distance isequal to or is smaller than a first threshold. The central controller134 controls the charging module 130 to perform wireless charging on theobject 2′ when the estimated distance is equal to or is smaller than asecond threshold.

Furthermore, the charging module 130 is used to enable the wirelesscharging device 13 to perform wireless charging on the object 2′.Therefore, the present invention is not limited to the implementation ofthe charging module 130. A person with ordinary skill in the art maymake any designs according to practical demands or applications.Therefore, the charging module 130 will not be described in detailherein. Moreover, since the implementation of the proximity sensor 132is similar to the proximity sensor 12 in FIG. 3A or FIG. 3B, theproximity sensor 130 will not be described in detail herein. It shouldbe noted that the proximity sensor 132 of the present embodiment can becontrolled to be permanently turned on since the proximity sensor 132has the advantage of low power consumption.

More particularly, as shown in FIG. 13, only the proximity sensor 130 iscontrolled to be permanently turned on at an initial stage. Meanwhile,the other modules or circuits (for example, the charging module 130) inthe wireless charging device 13 are controlled to be turned off Then, asthe object 2′ continuously moves closer to the wireless charging device13, the central controller 134 correspondingly controls the chargingmodule 130 in the wireless charging device 13 to be turned on if thecentral controller 134 determines that the estimated distance is equalto or is smaller than the first threshold (for example, 50 cm). When theestimated distance is equal to or is smaller than the second threshold(for example, 10 cm), the central controller 134 enables the chargingmodule 130 to perform wireless charging on the object 2′. On thecontrary, as the object 2′ continuously moves away from the wirelesscharging device 13, the central controller 134 stops the charging module130 from performing wireless charging on the object 2′ if the centralcontroller 134 determines that the estimated distance is larger than thesecond threshold (for example, 10 cm). When the distance is larger thanthe first threshold (for example, 50 cm), the central controller 134correspondingly controls the charging module 130 to be turned off.

As a result, the wireless charging device 13 can be prevented fromunnecessary power consumption to achieve energy saving. It should benoted that the above implementation only exemplifies, with no intentionto limit, the present invention. A person with ordinary skill in the artmay design the wireless charging device and the proximity sensoraccording to practical demands or applications.

On the other hand, according to the teachings stated above, a personwith ordinary skill in the art would understand that the centralcontroller 132 in the present embodiment may also control the wirelesscharging device 13 to execute other functions on the object 2′ accordingto the estimated distance. For example, the wireless charging device 13further includes a wireless transmission module (not shown). When thecentral controller 132 determines that the estimated distance is equalto or is smaller than a third threshold (for example, 30 cm), thecentral controller 132 may correspondingly turn on the wirelesstransmission module and enable the wireless charging device 13 toperform data transmission with other electronic devices (not shown)through the wireless transmission module.

Accordingly, the present invention provides a wireless charging device,capable of sensing a distance variation between the wireless chargingdevice and an object using a built-in proximity sensor and accordinglydetermining whether to turn on or turn off the charging module toachieve energy saving.

The above-mentioned descriptions represent merely the exemplaryembodiment of the present invention, without any intention to limit thescope of the present invention thereto. Various equivalent changes,alterations or modifications based on the claims of present inventionare all consequently viewed as being embraced by the scope of thepresent invention.

What is claimed is:
 1. A measurement device, comprising: a roller disposed at a bottom of said measurement device; at least one proximity sensor configured to sense a proximity status between said measurement device and an object and accordingly provide an estimated distance; a track sensing module disposed in said measurement device and configured to continuously capture a plurality of reference pictures of a regional surface of said roller and calculate a track length of said measurement device according to said plurality of reference pictures; an optical ranging module disposed in said measurement device and configured to emit a light beam towards the outside of said measurement device and calculate a distance data according to said light beam being reflected; and a processor coupled among said proximity sensor, said track sensing module and said optical ranging module and configured to selectively turn on or turn off said track sensing module and said optical ranging module according to said estimated distance; wherein said processor turns on said track sensing module and turns off said optical ranging module when said estimated distance is smaller than a first pre-determined threshold, and said processor turns off said track sensing module and turns on said optical ranging module when said estimated distance is larger than a second pre-determined threshold.
 2. The measurement device of claim 1, wherein said second pre-determined threshold is larger than or equal to said first pre-determined threshold.
 3. The measurement device of claim 1, wherein said track sensing module comprises: a light source configured to illuminate said regional surface of said roller; an image sensing circuit configured to capture said plurality of reference pictures of said regional surface illuminated by said light source based on a fixed sampling cycle; and an image analysis circuit configured to compare said plurality of reference pictures based on at least one textural feature of said plurality of reference pictures to acquire an illumination track of said light source on said roller and calculate said track length of said measurement device according to said illumination track.
 4. The measurement device of claim 1, wherein said proximity sensor comprises: an emitter unit configured to emit an optical signal; and a receiver unit configured to receive said optical signal being reflected and determine said proximity status between said measurement device and said object according to an intensity variation of said received optical signal to correspondingly provide said estimated distance.
 5. The measurement device of claim 1, wherein said proximity sensor comprises: an image capture unit configured to capture an image of said object; and a pixel processing unit coupled to said image capture unit and configured to calculate a number of pixel clusters occupied by said object according to said image and determine said proximity status between said measurement device and said object according to said number of pixel clusters to correspondingly provide said estimated distance.
 6. The measurement device of claim 1, wherein said optical ranging module comprises: a light-emitting device configured to emit said light beam towards the outside of said measurement device; an optical sensor device configured to sense and accumulate an energy of said light beam being reflected according to a shutter cycle signal to correspondingly provide an optical sensing signal; a control circuit configured to control said light-emitting device to continuously emit said light beam within a light-emitting period and switch said shutter cycle signal to a high level state within a sensing period after said light-emitting device has emitted said light beam for a delayed period, such that said optical sensor device senses and accumulates said energy of said light beam being reflected and accordingly provides said optical sensing signal; and a distance calculating circuit configured to acquire a time-of-flight (TOF) data according to said energy of said light beam emitted by said light-emitting device within said light-emitting period and said optical sensing signal and calculate said distance data according to said time-of-flight data.
 7. The measurement device of claim 6, wherein said light-emitting device is a light-emitting diode and said optical sensor device is a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (MOS) optical sensor device.
 8. The measurement device of claim 1, wherein said measurement device further comprises: a display module configured to display said distance data calculated by said optical ranging module and/or said track length calculated by said track sensing module.
 9. An operation method for a measurement device, wherein said measurement device comprises a roller, at least one proximity sensor, a track sensing module, an optical ranging module and a processor, said roller is disposed at a bottom of said measurement device and said operation method comprises steps of: using said proximity sensor to sense a proximity status between said measurement device and an object and accordingly provide an estimated distance; and using said processor to selectively turn on or turn off said track sensing module and said optical ranging module according to said estimated distance, wherein said processor turns on said track sensing module and turns off said optical ranging module when said estimated distance is smaller than a first pre-determined threshold, and said processor turns off said track sensing module and turns on said optical ranging module when said estimated distance is larger than a second pre-determined threshold.
 10. The operation method of claim 9, wherein said second pre-determined threshold is larger than or equal to said first pre-determined threshold.
 11. The operation method of claim 9, wherein, after said processor turns on said track sensing module, said operation method further comprises a step of: using said track sensing module to continuously capture a plurality of reference pictures of a regional surface of said roller and calculate a track length of said measurement device according to said plurality of reference pictures.
 12. The operation method of claim 9, wherein, after said processor turns on said optical ranging module, said operation method further comprises a step of: using said optical ranging module to emit a light beam towards the outside of said measurement device and calculate a distance data according to said light beam being reflected.
 13. A track sensing system, comprising: a base; a disk disposed on a surface of said base and being capable of being rotated and/or pressed on at least one portion on said disk by the user; a track sensing module disposed on a side of said disk and configured to continuously capture a plurality of reference pictures of a regional surface of said disk and calculate a displacement and/or a pressure of/on said disk rotated and/or pressed by the user according to said plurality of reference pictures; and a movement identification module configured to determine a movement of the user according to said displacement and/or said pressure.
 14. The track sensing system of claim 13, wherein said track sensing module comprises: a light source configured to illuminate said regional surface of said disk; an image sensing circuit configured to capture said plurality of reference pictures of said regional surface illuminated by said light source according to a fixed sampling cycle; and an image analysis circuit configured to compare said plurality of reference pictures based on at least one textural feature of said plurality of reference pictures to acquire an illumination track of said light source on said disk and calculate said displacement and/or said pressure of/on said disk rotated and/or pressed by the user according to said illumination track.
 15. The track sensing system of claim 13, wherein said base, said disk, said track sensing module and said movement identification module form an electronic device and said track sensing system further comprises a processor module disposed in said electronic device, wherein said processor module is configured to control said electronic device to execute a function corresponding to said movement. 